Refrigerator control



1951 E. R. TAYLOR EI'AL REFRIGERATOR CONTROL Filed Oct. 31, 1946 5 Sheets-Sheet 1 INVENTORJ [DWARD R. 72mm? Dow/11.0 F3 ARMBRUJTER g .ATTORNEYJ gal Aug. 14, 1951 E. R. TAYLOR ETAL- 2,563,973

REFRIGERATOR CONTROL Filed 001;. 31, 1946 5 Sheets-Sheet 4 A TTORNEYJ E. R. TAYLOR ETAL REFRIGERATOR CONTROL 5 Sheets-Sheet 5 Filed Oct. 31, 1946 a m a 3M TLU N N R R Me&0 W M T /R.R. T

Patented Aug. 14, 1951 REFRIGERATOR CONTROL Edward R. Taylor, Rocky River, and Donald P. Armbruster, Cleveland Heights, Ohio Application October 31, 1946, Serial No. 706,918

Claims.

This invention relates to improvements in refrigerator controls especially that type utilizing a liquid refrigerant adapted to be vaporized.

An object of the present invention is to catch the liquid refrigerant as it enters the vaporizing space and to utilize the weight of the liquid refriger'ant to control the opening and closing of the refrigerant admission valve.

Another object of the present invention is to provide novel means for counterbalancing the weight of the liquid refrigerant in the vaporizing chamber so that a very exact balance is obtained at all times, resulting in a nice adjustment of the refrigerant admission valve.

Our invention also provides novel means for insuring the automatic separation of the refrig erant from oil carried over from the compressor operation. This includes novel means for insuring that oil or other liquid-is returned to the compressor in sufficiently small increments so as to cause no damage to the compressor.

One of the advantages of our invention is its application to a beverage cooler, and therefore, our invention comprehends the placing of the beverage refrigerating coils within the liquid refrigerant reservoir. Where the beverage is beer, our invention includes the novel combination of a carbonatorin combination with the cooler.

Our invention also contemplates the application of the novel vaporizing chamber directly in a space to be refrigerated so that the refrigerating effect occurs outside of the housing rather than inside the same as in connection with a beverage cooler.

Our invention also contemplates the use of a single reservoir or container for both the liquid and vaporized refrigerant and the utilization of the Weight of this container to operate the refrigerant control valve directly. Since the use of such a container directly exposed to a refrigerated space will result in the accumulation of frost on the outer walls of the container, and since this will increase the weight of the container, we make use of this novel combination to provide automatic defrosting.

Another object of the present invention is to so multiply the forces acting in opposite directions on the refrigerant container as to provide an eflicient control even against resistant forces, such as flexible connections and the like, which might otherwise prevent the efficient operation of our device.

Still another object of our invention is to provide a mechanical advantage for the weight of the liquid refrigerant whereby the efiiciency of .our device is improved.

A still further use of our invention is found in the combination of a single control device in combination with a plurality of cooling chambers Lvhereby one device controls a plurality of chamers.

Other objects of our invention are the provision of a novel vapor space about the liquid refrigerant so as to reduce the radiation loss, and other novel combinations of structural features for carrying out the above-described purposes of our invention.

In the drawings,

Fig. 1 is a central sectional view through one embodiment of our invention, this view being taken along the line l-l of Fig. 2;

Fig. 2 is a top plan view of the device of Fig. 1;

Fig. 3 is a fragmental sectional view taken along the line 3-3 of Fig. 5;

Fig. 4 is a fragmental sectional view taken along the line 44 of Fig. 3;

Fig. 5 is a sectional view taken along the line 5-5 of Fig. 1;

Fig. 6 is a view similar to a portion of Fig. 1 and illustrating a modified form of our device;

Fig. 7 is another view similar to Figs. 1 and 6 and showing still another modification of our device; 4

Fig. 8 is a view of another modification of 0 device wherein both the liquid and vaporized refrigerant are in a single container, and the weight of this container is utilized directly to open and close the refrigerant admission valve;

Fig. 9 is another modification of our device wherein the refrigerant container is subjected to relatively strong forces acting in opposite directions so that lesser forces, such as the resistance of flexible tubes, may be readily overcome to provide efiicient controlling operations;

Fig. 10 is a further modification of our invention wherein the refrigerant container is given a mechanical advantage so as to more efliciently control the refrigerant admission valve;

Fig. 11 is a further modification of our invention wherein a single control device provides control means for a plurality of cooling chambers; while Fig. 12 is a further modification of our invention wherein the refrigerant admission valve is operated by snap action.

Referring first to Figs. 1 to 5 inclusive, we have illustrated one form of our invention wherein within a cooler II] we have mounted the housing l l providing a vaporizing chamber for a liquid refrigerant of the order of methyl chloride, although it will be understood by those skilled in this art that other vaporizable refrigerants might aseaovs be used. Our apparatus is intended to be used with a well known system, not shown, wherein a compressor withdraws vaporized refrigerant from the housing II and compresses the same, after which, it is cooled and condensed, and the liquid refrigerant is returned to the vaporizing chamber. Such systems are well known. The liquid refrigerant comes from the compressor through line I2 and a screen filter I3 to a volume control valve I4 and then to a refrigerant admission valve I5. The liquid refrigerant flows through the openings I5a and then through the tube I6 to a reservoir I1 which is mounted for vertical movement inside the housing II. This reservoir is in the form of a cup, open at the top, although other forms of our invention do not require this cup shape, as will later appear. The liquid refrigerant normally fills the reservoir up to a predetermined level, such as the dash-dotdot-dash line A which is determined by factors later described. As the refrigerant is vaporized to produce the desired cooling effect, it fills the upper portion of the cup, the annular space I8 around the sides of the reservoir and the space I9 below the reservoir. Through an outlet pipe 20 the vaporized refrigerant is carried back to the compressor, and this line contains a constant pressure valve 2I so as to hold the desired pressure inside the housing I I, as is customary.

The mounting of the reservoir I1 for vertical movement is accomplished in the present instance by arranging a central sleeve-like column I1a integral with the reservoir and liquid tight. Inside of this column is a sleeve 22 which is fixed to the base of the housing II. The members He and 22 thus guide the reservoir for its normal slight movement in a vertical direction. In this form of our device a spring 23 within the sleeve 22 presses a thimble 24 against the upper end of the column I1a so as to counterbalance the weight of the liquid refrigerant in the reservoir. This spring is held in place by the screw 25 which may be arranged to give an adjustment of spring tension, if necessary or desirable. An operative connection between the floating reservoir and the valve I5 is provided whereby as liquid refrigerant is vaporized, the reservoir will rise. urged by the spring 23, and this motion is utilized to open the valve I5 to admit more liquid refrigerant. When enough refrigerant has entered to cause the reservoir I1 to again move downwardly, compressing spring 23, valve I5 will again be closed. This operative connection comprises a lever 26 having one end housed in a pocket 21 secured to the top of the column I1a. This lever has a pivot at 28 intermediate its ends which is fixed relative to the housing II, as by means of the bracket 29. The other end of the lever is pivotally connected at 30 to the valve operator 3| extending upwardly through tube I6 and pivotally mounted at 32 on the valve I5. A compression spring 33 normally urges valve I5 in a valve opening direction. It will be noticed that the lever arm 2830 is much shorter than the lever arm from 28 to the bearing member 34 in the pocket 21. This gives a greater mechanical advantage in favor of the reservoir whereby the weight of the reservoir is multiplied many tismes to give effective closing movement of valve In adapting our device specifically for the cooling of a beverage, for instance beer, we have illustrated the positioning of the beverage cooling coils directly in the liquid refrigerant inside the reservoir I1. The warm beer is introduced through pipe which enters the housing II through a suitable fitting 86 shown in Fig. 2, but omitted from Fig. 1 for clearness. This is connected with pipe 81 inside the housing I I and extending downward through the open top of the cup shape reservoir I1. The outermost beer cooling coil 38 is a double coil, the lower ends of which are connected by a hairpin turn 38 indicated in dot-dash lines in Fig. 1. It results from this construction that the beer flows spirally downwardly through alternate coils 88a a returns spirally upwardly through the other rns 38b. As shown at the upper left-hand comer of this outer coil, it is connected as indicated in dot-dash lines at 40 with the intermediate beer cooling coil M. The beer then flows spirally downwardly again and then through a connection indicated in dot-dash lines at 42 to coil 43. The beer then returns upwardly to the outlet line 44 which extends out through the top of the cup and through a fitting 45 (Fig. 2) to a line, 46 which leads to the top of the carbonator 41. The outlet from the carbonator is through line 48 to abeer faucet 48. The nature of this carbonator will be better understood from a reference to Patent No. 2,125,248, granted July 26, 1938, to Edward R. Taylor.

A second coil for the cooling of water or the like is indicated. The warm water enters through line 50 and then through connection 5| on the top of housing I I, as indicated in Fig. 2, but this is omitted from Fig. 1 for clearness. The water passes downwardly through coil 52 and returns upwardly through coil 53 and then passes out through pipe 54 to a water faucet 55. It will be noted in Fig. 1 that the beverage coils are suitably suspended in a stationary condition by the use of one or more brackets 56 secured to the pocket 51 which is integral with the housing II. It is thus possible for the reservoir I1 to move upwardly and downwardly, as indicated by the dot-dash lines of Fig. 1 without disturbing the beverage cooling coils.

It will be noted that the carbonator 41 is, to a large extent, housed within the pocket 51, all sides of which are subject to the cooling action of the refrigerant. We are thus enabled to keep the carbonator cold at all times, which is of great advantage when the apparatus has stood unused for a period of time, such as overnight. The carbonator usually holds four or five cups of beer and therefore, the first beer drawn in the morning is cold.

It should be noted in Fig. 1 that there is an annular space between the recess 51 and the upper rim of the reservoir I1. This provides an upwardly attenuated area so that the liquid refrigerant, in boiling, does not easily splash out the top of the cup-shape reservoir.

We have provided automatic means for eliminating the oil which normally floats on the liquid refrigerant. To this end, we have provided an opening 58 through the wall of reservoir I1 slightly above the normal level A of the liquid refrigerant. The oil carried over from the compressor is lighter than the liquid refrigerant and floats on top of the same. Thus, it will take a slightly greater volume of refrigerant plus oil to balance spring 23 than would be the case if there were refrigerant only in the reservoir, In other words, when there is oil on top of the refrigerant, it raises the level A slightly, whereupon the oil drains out the opening 58 and falls to the bottom chamber I9 whence it is carried back to the compressor. Obviously, if other advantages were foregone, the rim of the cup I! might be placed at about the level of the hole 58 so that oil would drain over the top of the cup. It is within the scope of our invention to drain the oil either over the rim of the cup or through an opening in the wall of the cup.

We have provided a novel construction where the vapor leaves the housing II to enter the line 28 for its trip back tothe compressor so as to insure that at no time will a large amount of liquid be pumped back to the compressor so as to cause possible damage. This construction is most clearly shown in Figs. 3 and 4. Where the line is connected with the container i I for the removal of vapor therefrom, we have provided a baffle 59 which is in sealed relation to the container H above the line 20 and partly down the sides thereof, the bailie ending at a level slightly above the bottom of the container ll within the space N. This insures that the stream passing out the 'pipe 28 is continuously drawn from near the bottom of the space l9 and any small amounts of liquid such as oil or splashings of liquid refrigerant will immediately be picked up and taken away through pipe 28 so that only small amounts of liquid can be carried at any one time back to the compressor.

In Fig. 6 we have shown a further modification of our invention utilizing a weight in place of spring 23 for counterbalancing the refrigerant container. All of the parts of Fig. 6 which are like Fig. 1 and have the same function have been given the same reference characters and need not be further described here. The changes involved comprise the omission of spring 23 from the interior of sleeve 22. Instead, the bracket 21 has been extended as indicated at 21' to provide a bearing for the shorter arm of lever 68 which is pivotally mounted at 6! on the fixed bracket 62. The longer arm of lever 68 is engaged at the point 63 by a counterweight in the holder 64 which is supported for free vertical movement in the sleeve 65. The holder 64 may be filled with any suitable material for providing the desired weight needed to counterbalance the container I! along with its contents and connections. For in: stance, the holder 64 might be filled up to the level indicated by line 66 by liquid such as mercury or solid material such as shot, weights, or the like. They may be adjusted to any point desired.

The operation of the device of Fig. 6 is quite similar to that of the first described form. As the refrigerant within the container I 1 vaporizes, the container becomes lighter so that the counterweight applied at the point 63 is adapted to lift the container which in turn causes the lever 26 to move slightly in a counterclockwise direction about its pivot point 28 so as to move the valve operator 3| downwardly and to open the needle valve 85 which is connected to the upper end of the rod 3| as previously described. This will ad-- sired space and not limited to a beverage cooler.'

In this instance, a closed housing 81 of any shape desired encloses a reservoir 68 which contains liquid refrigerant 69 up to any suitable level, such as 18. Above this level the reservoir 68 is filled with vaporized refrigerant in the space H. In

the central portion of the reservoir is an upstanding hollow column 12, the upper end of which carries a bracket 13 which engages the longer arm of lever 14 which is pivoted at '15 on a fixed bracket 18. The shorter end of lever I4 is pivotally connected at 11 to red 18 which operates the refrigerant admission valve 19. Refrigerant enters through line Olifrom the compressor-condenser unit which is like that previously described. A spring 8| is mounted within a sleeve 82 and counterbalances the weight of the reservoir 68 with its contents and connections. Line 88 leads back to the compressor and may be provided with a constant pressure valve 84, although in the case of a domestic refrigerator this constant pressure valve would probably be omitted. Such devices are usually constructed of-such a size and capacity that when filled to normal level with refrigerant the proper cooling effect will be produced.

The operation of the device of Fig. 7 should now be clear. The housing 81 is directly in the chamber to be cooled and refrigerant flows into the reservoir 88 until spring 8! is overcome, causing lever 14 to move in a counterclockwise di rection until valve 19 is closed. When refrigerant has vaporized into the space 86 so that the weight of the reservoir 68 decreases, the spring 8i raises the reservoir so as to operate lever M to open valve 19 and admit more refrigerant. The vaporized refrigerant passes through line 83 back to the compressor.

In Fig. 8 we have shown how the weight of the refrigerant reservoir may be used directly to operate the refrigerant admission valve. Here the container 86 is entirely closed and normally has liquid refrigerant 81 up to a level 88 and above that the space 89 is filled with vaporized refrigerant. The reservoir 86 is mounted on a flexible bellows 98 supported on a fixed surface 9!. A spring 92 may be provided, if desired, to aid the bellows 98 in supporting the reservoir 88. This springis suitably guided both bottom and top and may be adjusted by means of nut 93 threaded on sleeve 94. The refrigerant admission pipe 95 communicates with the bottom of the bellows 98 and supports a fixed valve seat 96. Secured to the reservoir 86 is a needle valve 91 in position to coact with seat 96. Liquid refrigerant flows r into the bellows and through opening 98 into reservoir 86. Vapor is removed from the space 89 through a pipe 99 which has a liquid-tight connection with the support 9! and a slidable connection 188 with reservoir 86. This pipe is thus held fixed as the reservoir 86 moves up and down. The pipe 99 is connected back to the compressor. A small hole 99a may be provided just above the normal level of liquid refrigerant so that when oil collects on top of the refrigerant it will be pumped back to the compressor. Suitable means is provided such as the fixed guides llll for holding the reservoir 86 for free vertical movement.

The operation of the device of Fig. 8 should now be apparent. As more refrigerant enters the reservoir 86 it becomes heavier so as to overcome the bellows 98 and spring'92, causing valve 91 to close on its seat 96. As refrigerant vaporizes into the space 89 and is carried back to the compressor the reservoir becomes lighter until valve 91 is opened to admit more liquid refrigerant.

Fig. 8 illustrates an automatic defrosting arrangement. When the reservoir 86 is directly exposed to the cooling chamber a coating of frost I82 will form on the outer walls thereof. This adds to the weight of the reservoir 86 and, when the accumulation of frost has become suiilclently great, the amount of refrigerant 81 will gradually decrease as the weight of the frost closes valve 91 earlier. than would otherwise be the case. When the amount. of refrigerant in the reservoir 86 is out below a certain point the reservoir and the space around it will become warmer so that the frost I02 will be melted off the outside of the reservoir 86. When this occurs the normal amount of liquid refrigerant will again be necessary within the reservoir 86 to overcome the counterbalancing bellows and spring so that the device will again cool as originally intended.

In the modification of Fig. 9, a reservoir I03 holds liquid refrigerant I04 in the lower portion thereof and vaporized refrigerant in the space I05. Here the container is counterbalanced by the bellows I06 and spring I01 as described in connection with Fig. 8. The refrigerant admission line I08 supports a fixed valve seat I09 which cooperates with needle valve H in the same fashion as described in Fig. 8. The line I I I leading back to the compressor is here connected directly to the top of reservoir I03 by means of a flexible connection II2. If this device of Fig. 9 were like that of Fig. 8 the forces acting to open and close the valve IIO would be very slight, namely, the weight of the reservoir I03 and a few pounds of refrigerant inside the same. This might not be sufficient to overcome the flexible connection II2 so as to give efiicient operation. We have therefore provided a very strong spring I01, say exerting a force of one hundred pounds upwardly from the fixed support II3. We then provide another strong spring II4 acting downwardly from the fixed support II against the reservoir I03. This spring I I4 may exert a force say of ninety-nine pounds. These strong springs overcome the resistance of the flexible connection II2 very easily so that the movement of reservoir I03 is not hampered in any way. It therefore takes only one pound difference in the weight of liquid refrigerant indicated at I04 to operate the valve IIO. In other respects, this device operates like that of Fig. 8.

In Fig. 10, we have shown an arrangement whereby the refrigerant container is given a mechanical advantage for operating the refrigerant admission valve. Here the reservoir IIB has liquid refrigerant H1 in the lower portion thereof and vaporized refrigerant in the space II8 above. The line H9 is connected directly to the reservoir to conduct vaporized refrigerant back to the compressor. A flexible connection I20 is provided in this line. The liquid refrigerant communicates through pipe I2I at the bottom of the reservoir to a fitting I22 attached to the bottom of closed bellows I23 which is mounted on the fixed support I24. The refrigerant admission pipe I25 supports a fixed valve seat I26. The fitting I22 supports needle valve I21 for cooperation with the seat I25. The pipe I2I is pivotally mounted at I28 on a fixed bracket I29. A spring I30 is held in compression between the support I24 and pipe I2I so as to normally urge valve I21 in opening direction.

It will now be apparent from consideration of Fig. that the reservoir H9 working on a lon lever arm about the pivot point I28 will provide any desired mechanical advantage through the shorter lever arm to close the valve I21. As the refrigerant III vaporizes, the reservoir II6 becomes lighter until spring I30 overcomes the weight of the reservoir and opens valve I21 to admit more liquid refrigerant. When the balance is again restored, the weight of the reservoir is suflicient to close valve I21.

In Fig. 11 we have illustrated at the right-hand end thereof a reservoir 86' constructed, supported and operated in all respects exactly like the reservoir 86 of Fig. 8 except for the liquid refrigerant connection I3I. This leads through a flexible connection I32 and suitable piping I33 and I33 to the lower portion of closed containers I34 and I35. The reservoir 86 is filled with liquid refrigerant up to the level 88 and, through the equalizing connections I3I and I33, the liquid will then be at the same level in the containers I34 and I35. The pipe 99 for leading vaporized refrigerant back to the compressor is connected to a manifold I36 which in turn is connected at I 31 and I38 to the upper portion of containers I35 and I34, respectively. Thus, vaporized refrigerant is conducted from the spaces I39 and I40 back to the compressor.

The operation of the equipment shown diagrammatically in Fig. 11 should now be clearly understood. The containers I34 and I35 may be located in separate cooling chambers where each provides its own cooling effect while being controlled from a single reservoir 86'. As the liquid refrigerant in the reservoir 86' becomes reduced byvaporization, the bellows and spring 92 serve to lift the reservoir so as to open valve 91 and admit more refrigerant to reservoir 86. and at the same time, to the containers I34 and I35. The reservoir 86 is permitted to move up and down by the flexible connection I32. When it becomes heavy enough it will then overcome the bellows 90 and spring 92 to close valve 91 cutting off the admission of liquid refrigerant.

In Fig. 12 we have shown a device which is operable by snap action. Here the container I4I is adapted to hold liquid refrigerant in the lower portion thereof at I4 Ia up to a level indicated at I42 which will vary somewhat according to the teachings of this invention. Above this level the upper portion I4 Ibis filled with vaporized refrigerant. A fiexible conduit I43 is connected back to the compressor as in previous forms of our device. The admission of liquid refrigerant to the lower portion of the container is through line I44,

valve I45 and flexible line I46. The major portion of the weight of the container MI and its contents and connections is balanced by a sprin I41 which is supported on a fixed base I48. The container is rigidly connected with the longer arm I49a of a bell crank which has a fixed pivot at I50 on a fixed bracket I5I. The short arm of the bell crank I49b has a pin and slot connection I52 with a link I53 which is pivotally mounted at I54 on the fixed bracket I55. A link I55 is pivotally connected at I51 with the link I53 and is pivotally connected at I58 with the valve I 45. A spring I59 is connected between pin I51 and a fixed pin I60 on the fixed base I6I. The operation of this form of our device should now be apparent. With the parts in the position shown in Fig. 12, enough refrigerant has vaporized to lighten the container I4I so that it is moved upwardly urged by spring I41 so as to open valve I45 and admit additional liquid refrigerant to the space I4Ia. As the container becomes heavier, due to the admission of liquid refrigerant, it will move downwardly carrying the bell crank arm I49 in a clockwise direction about the pivot I50. This will carry link I53 toward the right, as viewed in Fig. 12, until spring I59 passes to the right of the pivot I54, after which, the

link I53 will move in a counterclockwise direction with a snap action, this movement being permitted by the pin and slot connection I52. This will close the valve I45 stopping the flow of refrigerant. When refrigerant has vaporized into the space I IIb so that the container becomes lighter, it will be urged upwardly by spring I41 which will carry the bell crank arm 9b in a counterclockwise direction, at which time, the pin I52 will move to the left-hand end of the slot I52a. A slight movement of arm "9b in a counterclockwise direction will then carry spring I59 slightly to the left of pivot I54 substantially as shown in Fig. 12, whereupon spring I59 will open valve I45 with a snap action which is permitted by the pin and slot connection.

What we claim is:

1. In a device utilizing a vaporizable refrigerant, the combination of chamber means for containing refrigerant vapor, a reservoir for liquid refrigerant in said chamber, means, said reservoir being mounted for vertical movement as its weight becomes lighter or heavier, a liquid refrigerant supply for said reservoir including a control valve therefor, an operative connection between said reservoir and said valve for opening and closing said valve respectively by rise and fall of said reservoir, counterbalancing means operatively connected with said reservoir for causing the latter to rise when the weight of said reservoir and its content of liquid refrigerant is less than a predetermined amount, and fluid cooling coils in said liquid refrigerant within said reservoir.

2. In a device utilizing a vaporizable refrigerant, the combination of chamber means for containing refrigerant vapor, a reservoir for liquid refrigerant in said chamber means, said reservoir being mounted for vertical movement as its weight becomes lighter or heavier, a liquid refrigerant supply for said reservoir including a control valve therefor, an operative connection between said reservoir and said valve for opening and closing said valve respectively by rise and fall of said reservoir, counterbalancing means operatively connected with said reservoir for causing the latter to rise when the weight of said reservoir and its content of liquid refrigerant is less than a predetermined amount, there being a recess in said reservoir cooled by said refrigerant, and a fluid flow tank positioned in said recess.

3. In a device utilizing a vaporizable refrigerant, the combination of chamber means for containing refrigerant vapor, a reservoir for liquid refrigerant in said chamber means, said reservoir being mounted for vertical movement as its weight becomes lighter or heavier, valve means for controlling refrigerant flow and responsive to reservoir movement, there being an opening provided leading out of said reservoir at approximately the top level of liquid refrigerant in said 10 reservoir, whereby to drain oif oil floating on said liquid refrigerant, and a drain leading out of said chamber means below said opening for removing said oil,

4. In a device utilizing a vaporizable refrigerant, the combination of chamber means for containing refrigerant vapor, a reservoir for liquid refrigerant in said chamber means, an inlet for liquid refrigerant leading directly into said reservoir, said reservoir being mounted for vertical movement as its Weight becomes lighter or heavier, means counterbalancing the weight of said reservoir and contents, valve means for controlling refrigerant flow through said inlet and having an operative connection with said reservoir, whereby said valve means is responsive to reservoir movement, said counterbalancing means being so chosen as to be overcome by the weight of said reservoir when less than completely filled with liquid refrigerant, whereby said valve means is closed and said chamber means outside of said reservoir remains substantially free of liquid refrigerant.

5. In a device utilizing a vaporizable refrigerant, the combination of chamber means for containing refrigerant vapor, a reservoir for liquid refrigerant in said chamber means, an inlet for liquid refrigerant leading directly into said reservoir, said reservoir being mounted for vertical movement as its weight becomes lighter or heavier, means counterbalancing the weight of said reservoir and contents, valve means for controlling refrigerant flow through said inlet and having an operative connection with said reservoir, whereby said valve means is responsive to reservoir movement, said coimterbalancing means being so chosen as to be overcome by the weight of said reservoir when less than completely filled with liquid refrigerant, whereby said valve means is closed and said chamber means outside of said reservoir remains substantially free of liquid refrigerant, and a vapor outlet communicating with the bottom of said chamber means.

EDWARD R. TAYLOR. DONALD P. ARMBRUS'I'ER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,174,221 Bachman Mar. 7, 1916 1,581,158 Beach Apr. 20, 1926 1,746,026 Browne Feb. 4, 1930 1,826,791 Kellogg Oct. 13, 1931 2,019,605 Guyton Nov. 5, 1935 2,051,802 Philipp Aug. 18, 1936 2,434,374 Tull Jan. 13, 1948 FOREIGN PATENTS Number Country Date 252,647 Great Britain May 28, 1926 

